On Wed, Mar 10, 2021 at 05:53:04PM -0600, Bjorn Andersson wrote:
> On Wed 10 Mar 15:10 CST 2021, Mathieu Poirier wrote:
>
> > When a remote processor that was attached to is stopped, special care
> > must be taken to make sure the shutdown process is similar to what
> > it would be had it been started by the remoteproc core.
> >
> > This patch takes care of that by making a copy of the resource
> > table currently used by the remote processor. From that point on
> > the copy is used, as if the remote processor had been started by
> > the remoteproc core.
> >
> > Signed-off-by: Mathieu Poirier <mathieu.poirier@xxxxxxxxxx>
> > ---
> > New for V7:
> > New Patch, used to be part of 11/16 in V6.
> > ---
> > drivers/remoteproc/remoteproc_core.c | 53 +++++++++++++++++++++++++++-
> > 1 file changed, 52 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/remoteproc/remoteproc_core.c b/drivers/remoteproc/remoteproc_core.c
> > index e9ea2558432d..c488b1aa6119 100644
> > --- a/drivers/remoteproc/remoteproc_core.c
> > +++ b/drivers/remoteproc/remoteproc_core.c
> > @@ -1634,6 +1634,52 @@ static int rproc_reset_rsc_table_on_detach(struct rproc *rproc)
> > return 0;
> > }
> >
> > +static int rproc_reset_rsc_table_on_stop(struct rproc *rproc)
> > +{
> > + struct resource_table *table_ptr;
> > +
> > + /* A resource table was never retrieved, nothing to do here */
> > + if (!rproc->table_ptr)
> > + return 0;
> > +
> > + /*
> > + * If a cache table exists the remote processor was started by
> > + * the remoteproc core. That cache table should be used for
> > + * the rest of the shutdown process.
> > + */
> > + if (rproc->cached_table)
> > + goto out;
> > +
> > + /* Remember where the external entity installed the resource table */
> > + table_ptr = rproc->table_ptr;
> > +
>
> Afaict this is just a remnant from the detach case.
>
> I think the series looks really good now, please let me know and I can
> drop the local "table_ptr" as I apply the patches.
(sigh) No matter how long you stare at a patchset there is always one that gets
away. I will address Arnaud's comment and fix this in a new revision.
Thanks,
Mathieu
>
> Regards,
> Bjorn
>
> > + /*
> > + * If we made it here the remote processor was started by another
> > + * entity and a cache table doesn't exist. As such make a copy of
> > + * the resource table currently used by the remote processor and
> > + * use that for the rest of the shutdown process. The memory
> > + * allocated here is free'd in rproc_shutdown().
> > + */
> > + rproc->cached_table = kmemdup(rproc->table_ptr,
> > + rproc->table_sz, GFP_KERNEL);
> > + if (!rproc->cached_table)
> > + return -ENOMEM;
> > +
> > + /*
> > + * Since the remote processor is being switched off the clean table
> > + * won't be needed. Allocated in rproc_set_rsc_table().
> > + */
> > + kfree(rproc->clean_table);
> > +
> > +out:
> > + /*
> > + * Use a copy of the resource table for the remainder of the
> > + * shutdown process.
> > + */
> > + rproc->table_ptr = rproc->cached_table;
> > + return 0;
> > +}
> > +
> > /*
> > * Attach to remote processor - similar to rproc_fw_boot() but without
> > * the steps that deal with the firmware image.
> > @@ -1759,7 +1805,12 @@ static int rproc_stop(struct rproc *rproc, bool crashed)
> > rproc_stop_subdevices(rproc, crashed);
> >
> > /* the installed resource table is no longer accessible */
> > - rproc->table_ptr = rproc->cached_table;
> > + ret = rproc_reset_rsc_table_on_stop(rproc);
> > + if (ret) {
> > + dev_err(dev, "can't reset resource table: %d\n", ret);
> > + return ret;
> > + }
> > +
> >
> > /* power off the remote processor */
> > ret = rproc->ops->stop(rproc);
> > --
> > 2.25.1
> >
